The South African government has outlined 1, 600MW of new additional capacity will be coming on line every year from wind energy as part of their new energy plan. But how exactly do those turning blades result in your kettle boiling at home?
According to Explain That Stuff, a wind turbine’s blades spin when wind blows past them. The wind loses kinetic energy which is gained by the turbine. This is then stored by the turbine for use as part of the national power grid. Since wind speeds can vary, and higher wind speeds mean more energy, turbines are often set up in “farms” to keep the supply closer to constant.
Here are the steps to how a wind turbine works:
- Wind blows the turbines blades.
- The blades turn, capturing kinetic energy and turning the drive shaft (also called the rotor) they’re connected to.
- Some wind turbines can swivel to face the best angle to meet the wind. This is done with a pitch control mechanism.
- The main body of the turbine (nacelle) sitting behind the blades contains the gearbox, generator, anemometers (speed measuring devices), brakes and transformers. The gearbox converts the low-speed rotation of the drive shaft into high-speed rotation to drive the generator.
- The generator takes the kinetic energy and turns it into electrical energy.
- The electric current produced by the generator flows through a cable running down through the inside of the turbine tower.
- The anemometers and wind vanes measure the wind speed and direction.
- A yaw motor underneath the nacelle controls which way the nacelle faces to capture the most electricity and brakes stop the rotors from turning if necessary.
- A step-up transformer converts the electricity to a higher voltage so it can be transmitted efficiently to the power grid.